Sliding-door latching and locking device



SLIDING-DOOR LATCHING AND LOCKING DEVICE Filed May 9, 1966 58 44 FIG. 5.54

FIG-4.

lNl/EN TOR ARTHUR G. D/ACK 5y HIS A rraeA/Evs HARRIS, K/EcH, RussELL &KERN United States Patent 3,395,490 SLIDING-DOOR LATCHING AND LOCKINGDEVICE Arthur G. Diack, 1049 E. 65th St., Inglewood, Calif. 90302 FiledMay 9, 1966, Ser. No. 548,514 7 Claims. (Cl. 49-449) ABSTRACT OF THEDISCLOSURE A latching and locking device for horizontally movable,bypassing sliding doors, comprising a latch element pivotable about avertical axis in a slot in one of the doors and insertable into anotherslot in the other door to latch the two doors together against relativehorizontal and relative vertical movement. The latch element may belocked in its inserted position.

Summary and objects of invention The present invention relates to asliding-door latching and locking device and primary objects of theinvention are to provide a device which permits the door to move freelybetween its open and closed positions, which include means for latchingthe door in its closed position automatically upon movement of the doorinto its closed position, which includes means for locking the door inits closed position, and which includes means for locking the dooragainst removal from its track means when it is locked in its closedposition.

Another primary object of the invention is to provide a device usablewith bypassing sliding doors which permits free movement of both doorsbetween their closed and open positions, which automatically latchesboth doors together in their closed positions upon movement thereof intotheir closed positions, which locks both doors together in their closedpositions, and which locks both doors against removal from theirrespective track means when they are locked together in their closedpositions.

Since the invention is particularly applicable to the bypassing slidingdoors of show cases, it will be considered in connection therewith forconvenience. However, it will be understood that the invention may beused in connection with bypassing sliding doors in other environments,and may, in some instances, be used in conjunction with single doors.

Considering the invention more specifically now, important objectsthereof are to provide a showcase, or other structure, which includes:parallel first and second track means; first and second bypassingsliding doors respectively movable along the first and second trackmeans; first and second latch elements respectively carried by the firstand second doors and interengageable when the doors are in their closedpositions, the second latch element preferably being formed by a latchrecess in the second door into which the first latch element isinsertable to lock the doors together when the doors are in their closedpositions; means mounting the first latch element on the first door formovement between an extended position, wherein it is insertable into thelatch recess when the doors are in their closed positions, and aretracted position; means biasing the first latch element toward itsextended position so that it automatically tends to enter the latchrecess in the second door when the doors are in their closed positionsto lock the two doors together; means for locking the first latchelement in its retracted position to prevent engagement thereof with thelatch recess in the second door when the two doors are in their closedpositions; means for locking the first latch element in its extendedposition when the doors are closed and the first latch element isinserted into the latch ice recess in the second door, such lockingmeans preferably being key operated so that the doors cannot be unlockedfor movement to their open positions without the necessary key; andmeans on the first door and operable concurrently with the locking meanslast mentioned for interlocking the first door and the first track meansso that the doors are locked together and interlocked with the firsttrack means against lateral removal of the doors from their track meanswhen the doors are closed and locked together by the first latch elementon the first door and the latch recess in the second door.

With the foregoing construction, the latching and locking device of theinvention performs four important functions, as follows:

First, by locking the first latch element in its retracted position, thelatching device of the invention is rendered inoperative. Consequenlty,the showcase may be opened and closed by the sales person in chargethereof without any interference by the device of the invention.

Second, by leaving the first latch element free to move into itsextended position under the influence of its biasing means, the showcasedoors are automatically latched in their closed positions upon movementthereof into such positions. This is very desirable to minimize thepossibility of shoplifting in the event that the sales person in chargehas to leave the showcase unattended, as while waiting on a customersome distance away. Stores find that if the doors of showcasescontaining relatively small and valuable articles are left unlatched orunlocked while such showcases are unattended, shoplifting losses arehigh since it is a simple matter for a shoplifter to reach over the topof the showcase, slide one of the doors open, remove one or morearticles from the top shelf of the showcase by reaching over the topthereof, and escape undetected. The present invention minimizes thepossibility of shoplifting losses of this nature by providing means forautomaticallylatching the showcase doors in their closed positions uponclosure thereof,

Third, by actuating the key-operated locking means for locking the firstlatch element in the latch recess with the doors closed, the doorscannot be opened by anyone not having the necessary key. Thus, theshowcase can be locked against entry by unauthorized persons, as whenclosing the store for the night.

Fourth, since the aforementioned key-operated locking means also locksthe first door to its track means, as well as locking the two doorstogether, the showcase cannot be entered by removing one or both doorsfrom the corresponding track means. Consequently, the showcase ispositively locked against anything but forcible entry.

Other important objects of the invention are to provide a latching andlocking device of the foregoing nature wherein: the first latch' elementis pivotally mounted in a slot through the first door for pivotalmovement, about a pivot axis parallel to the plane of the first door andperpendicular to the direction of movement thereof, between an extendedposition at an acute angle to the first door and a retracted positionparallel to and within the first door; wherein the latch recess in thesecond door is a latch slot adapted to receive the first latch elementwhen the doors are in their closed positions; and wherein the lockingmeans for locking the first latch element in its extended and retractedpositions and for locking the first door to its track means are alldisposed within the first door and are actuated by a single key-operatedlock located substantially entirely within the first door. A relatedobject is to provide a construction wherein the locking means for thefirst latch element comprise a locking element mounted within the firstdoor for rotation between operative and inoperative positions andengageable with opposed surfaces of a locking projection on the firstlatch element when in its operative position to lock the first latchelement in its retracted and extended positions, respectively.

The foregoing construction provides a very compact latching and lockingdevice all moving parts of which are located substantially entirelywithin the first door, which is an important feature of the invention. Arelated object is to provide a latching and locking device all movingparts of which are mounted substantially entirely within the bottom railof a glass showcase door, thereby providing a very inconspicuousinstallation readily accessible only to authorized persons, andinaccessible to potential shoplifters from the front of the showcase.

The foregoing objects, advantages, features and results of the presentinvention, together with various other objects, advantages, features andresults thereof which will be evident to those skilled in the art towhich the invention relates in the light of this disclosure, may beachieved with the exemplary embodiment of the invention described indetail hereinafter and illustrated in the accompanying drawing.

Description of the drawing FIG. 1 is a fragmentary isometric view of therear of a showcase having bypassing sliding glass doors the bottom railsof which incorporate the latching and locking device of the invention;

FIG. 2 is a fragmentary horizontal sectional view taken as indicated bythe arrowed line 2-2 of FIG. 1, and showing a first latch element of theinvention locked in its extended position to lock the two doorstogether;

FIG. 3 is a fragmentary vertical sectional view taken as indicated bythe arrowed line 33 of FIG. 2;

FIG. 4 is a fragmentary vertical sectional view taken as indicated bythe arrowed line 44 of FIG. 2 and showing locking means in positions tolock the first latch element in its extended position and to lock thedoors to their track means;

FIG. 5 is a fragmentary horizontal sectional view similar to FIG. 2, butshowing the first latch element locked in its retracted position topermit the doors to be opened and closed freely; and

FIG. 6 is a view similar to FIG. 4, but showing the means for lockingthe doors to their track means in a position to permit removal of thedoors therefrom.

Detailed description of exemplary embodiment bf invention Referringinitially to FIG. 1 of the drawing, fragmentarily illustrated therein isa frame 10 for bypassing sliding doors :12 and 14 which may be locatedat the rear of a showcase, the front of a display cabinet, or the like.For convenience, the doors 12 and 14 will be regarded as located at therear of a showcase and will be referred to hereinafter as front andrear, or second and first, doors, respectively.

The frame 10 includes an upper rail 16 provided therein with downwardlyfacing front and rear channels 18 and 20 for the upper edges of thefront and rear doors 12 and 14, respectively. The front and rear doors12 and 14 respectively comprise front and rear glass panels 22 and 24the respective lower edges of which are disposed in upwardly facingchannels 26 and 28 of front and rear lower rails 30 and 32 of therespective doors 12 and 14. The front and rear lower rails 30 and 32respectively include downwardly facing channels 34 and 36 containingwheels for supporting the respective doors 12 and 14, one of the wheelsin the channel 34 being visible in FIG. 1 of the drawing and beingdesignated by the numeral 38.

The front and rear doors 12 and 14 ride on front and rear track means 42and 44 respectively disposed in front and rear channels 46 and 48 in alower rail 50 of the frame 10. The track means 42 and 44 respectivelyinclude rib-like tracks 52 and 54 on which the wheels on the doors 12and 14 run, the wheels being grooved to receive the tracks.

It will be noted that the lower rails 30 and 32 of the doors 12 and 14are H-shaped and respectively include horizontal webs 56 and 58respectively separating the upper and lower channels of such rails.

The foregoing structure of the frame 10 and the bypassing sliding doors12 and 14 is conventional. The present invention resides in means 60 forlatching and locking the doors :12 and 14 together in their closedpositions, and for locking the doors against lateral removal from theirtracks 52 and 54, as will now be described in detail.

The basic component of the latching and locking means or device 60 is alatch element 62 which is carried by the door 14 and which is preferablypivotable into and out of a latch recess 64 in the door 12 when the twodoors are in their closed positions. The latch element 62 is pivotableabout an axis parallel to the plane of the door 14 and perpendicular tothe direction of movement thereof in a manner to be described. When thelatch element 62 is in its extended position, shown in FIG. 2,: it isdisposed at an acute angle to the door 14 and is inserted into the latchrecess 64. When the latch element 62 is in its retracted position, shownin FIG. 5, it is disposed within and parallel to the door 14.

More particularly, the latch element 62 is a relatively thin, flat,elongated strip disposed in a complementary slot 66 through the bottomrail 32 of the door 14 just below the web 58 thereof. The latch element62 is pivotally connected intermediate its ends to the web 58 by a pivot68 oriented to provide the hereinbefore-defined pivot axis. The latchrecess 64, which receives one end of the latch element 62 therein whenthe doors 12 and 14 are closed and the latch element is in its extendedposition, has the form of a slot in one wall of the channel 34 in thebottom rail 30 of the door 12. The latch slot 64 is located just belowthe web 56 of the rail 30* and registers with one end of the slot 66when the doors 12 and 14 are closed. The latch slot 64 is complementaryto the latch element 62 so that there is a relatively close fit betweenthe upper and lower surfaces of the latch element and the upper andlower edges of the latch slot when the doors are closed and the latchelement is extended. Consequently, the two doors 12 and 14 are lockedtogether in the vertical direction so that neither can be lifted withoutlifting the other. As best shown in FIG. 2, the end of the latch element62 within! the latch slot 64 is engageable with one end of the latchslot to prevent horizontal opening movement of either door. Thus, thelatch element 62, when inserted into the latch slot 64, cooperates withthe latch slot to lock the two doors together both vertically and in thedirections of opening movement of the doors.

In instances where the foregoing vertical interlock of the doors 12 and14 is not desired, the latch element 62 may be so located that it merelyengages the edge 69 of the door 12, instead of entering the latch slot64. In such a case this slot may be omitted, and the door edge 69 actsas a latch element.

The latch element 62 is biased toward its extended position, shown inFIG. 2, by a rattrap spring 70 coiled around a downward extension of thepivot 68. One end of the spring 70 is suitably secured to the latchelement 62 at 72, while the other end thereof bears against one wall ofthe channel 36 at 74. With this construction, as long as the latchelement 62 is free to pivot, it will automatically enter the latch slot64 to latch the doors 12 and 14 closed upon movement thereof into theirclosed positions. This is an important antishoplifting feature, ashereinbefore outlined.

The latch element 62 is provided thereon, adjacent the end thereofopposite the end insertable into the latch slot 64, with a manualactuator tab 76 projecting rearwardly through the slot 66. As will beapparent, the doors 12 and 14 can be unlatched readily merely by pushingforwardly on the actuator tab 76. The sales person can do this readilywith his or her toe if desired, it being unnecessary to bend over tounlatch the doors.

Thus, the invention provides a very simple and positive means forlatching the doors 12 and 14 closed automatically upon closure thereof.At the same time, the two doors are positively interlocked bothvertically and horizontally in their directions of opening movement. Thedoors 12 and 14 may be unlatched very simply merely by pushing forwardlyon the actuator tab 76.

The invention also provides means 80 for locking the latch element 62 inits retracted position, shown in FIG. 5, to prevent automatic latchingof the doors 12 and 14 upon movement thereof into their closedpositions. This feature is highly desirable where the showcase isattended by a sales person who finds it necessary to open and close thedoors frequently.

Considering the locking means 80 more specifically, :it includes anaxially-short lock 82 of conventional construction operable by a key 84.The lock 82 is disposed substantially entirely within the bottom rail 32of the door 14, extending into the interior of such bottom rail througha hole 86 drilled into the rear walls of the channels 28 and 36-. Theweb 58 is also provided with an opening 88 therein in the vicinity ofthe hole 86 to accommodate the lock 82. The lock is secured in place byclamping the periphery of the hole 86 between two threadedly connectedparts of the lock, as will be clear from FIGS. 2, 3 and 5.

Connected to the lock 82 is a locking element 90 which is rotatable froman operative position, shown in FIGS. 2, 4 and 5, to an inoperativeposition, shown in FIG. 6, upon corresponding rotation of the key 84.Referring to FIG. 5, when the locking element 90 is in its operativeposition and the latch element 62 is in its retracted position, thelocking element 90 engages one edge 92 of a locking projection 94 at theend of the latch element 62 opposite the end thereof which is insertableinto the latch slot 64. Interengagement of the locking element 90 andthe edge 92 of the locking projection 94, as shown in FIG. 5, locks thelatch element 62 in its retracted position. Consequently, under suchconditions, the doors 12 and 14 are free to slide between their open andclosed positions without interference by the latching and locking device60 of the invention.

When it is desired to provide for automatic latching of the doors 12 and14 in their closed positions, the key 84 is turned as required to placethe locking element 90 in its inoperative position, as shown in FIG. 6.This releases the latch element 62 so that it is free to enter the latchslot 64 each time the doors 12 and 14 are moved into their closedpositions, thereby latching them closed automatically.

Another locking means 96 is provided for locking the doors 12 and 14 intheir closed positions whenever locking of the showcase is desired, aswhen closing the store for the night. The locking means 96 includes thelocking element 90 and an edge 98 of the locking projection 94 oppositethe edge 92 thereof. More particularly, with the latch element 62 in itsextended position wherein it is inserted into the latch slot 64, the key84 can be turned to position the locking element 90 in engagement withthe edge 98 of the locking projection 94, as shown in FIGS. 2 and 4.Under these conditions, the latch element 62 is locked in its extendedposition to interlock the two doors 12 and 14 in the manner hereinbeforediscussed.

Thus, it will be apparent that the locking element 90 can be positionedin its inoperative position, shown in FIG. 6, to permit automaticlatching of the doors 12 and 14, or it can be positioned in engagementwith the edge 92 of the locking projection 94 to prevent automaticlatching, or it can be positioned in engagement with the edge 98 of thelocking projection to lock the doors closed. This triple function of thelocking element is an important feature of the invention.

Considering another important feature, sliding door installations of thenature under consideration .must provide clearances between the upperedges of the doors 12 and 14 and their guiding channels 18 and 20sufficient to permit lifting the doors from their tracks 52 and 54 andout of the frame 10. Because of these clearances, it is conceivable thatthe doors 12 and 14 might be lifted out of the frame 10 by a thief toprovide access to the interior of the showcase, even though the latchelement 62 is locked in its extended position by the locking element 90to interlock the two doors in their closed positions.

To prevent removal of the doors 12 and 14 from the frame 10, even thoughlocked together, the invention provides the lock 82 with a secondlocking element 100, shown as formed integrally with the locking element90, which is located forwardly of the track 54 and which depends belowthe top of such track a substantial distance, as shown in FIGS. 3 and 4,when the locking element 90 is in its operative position. The distancewhich the locking element 100 depends below the top of the track 54exceeds the distance that the doors 12 and 14 can be lifted from theirtracks 52 and 54 as the result of the clearances provided at the upperedges of the doors.

Consequently, when the latch element 62 is locked in its extendedposition by the locking element 90 to interlock the doors 12 and 14, thelocking element 100 depends below the top of the track 54 sufficientlyto prevent laterally rearward removal of the doors 12 and 14 from theirtracks 52 and 54. Therefore, unauthorized access to the showcase cannotbe achieved by lifting the locked doors 12 and 14 out of the frame 10,which is an important feature of the invention. (In this connection, itwill be understood thatthe frame 10 includes structure, not shown, forpreventing laterally forward or inward removal of the doors 12 and 14when closed.)

When it is desired to remove the doors 12 and 14 from their tracks 52and 54, the key 84 is turned to place the locking elements 90 and 100 inthe positions shown in FIG. 6. The length of the locking element 90 isinsufiicient to permit it to engage the track 54, so that the door 14can be removed readily.

Thus, the latching and locking device 60 of the invention achieves itsimportant functions of permitting free movement of the doors 12 and 14between their closed and open positions, of automatically latching bothdoors together in their closed positions upon movement thereof into suchposition, of locking the doors together in their closed positions. andof locking the doors against removal from their respective tracks whenthey are locked together in their closed positions.

Although an exemplary embodiment of the invention has been disclosedherein for purposes of illustration, it will be understood that variouschanges, modifications and substitutions may be incorporated in suchembodiment without departing from the spirit of the invention as definedby the claims which follow.

I claim as my invention:

1. In combination:

(a) first and second bypassing slitting doors;

(b) first and second latch elements respectively carried by said firstand second doors and interengageable when said doors are in their closedpositions;

(c) means pivotally mounting said first latch element on said first doorfor pivotal movement, about a pivot axis parallel to the plane of saidfirst door and perpendicular to the direction of movement thereof,between an extended position, wherein said first latch element isdisposed at an acute angle to said first door and is engageable withsaid second latch element when said doors are in their closed positions,and a retracted position wherein said first latch element is disposedparallel to said first door;

((1) said first latch element being pivotally mounted in a slotextending through said first door, and said second latch element beingformed by a latch slot in said second door into which said first latchelement is insertable to lock said doors together when said doors are intheir closed positions and said first latch element is in its extendedposition; and

(e) means biasing said first latch element toward its extended position.

2. The combination set forth in claim 1 wherein said first latch elementis provided With a manual actuator on the side of said first dooropposite said second door.

3. The combination set forth in claim 1 including means for locking saidfirst latch element in its retracted position.

4. The combination set forth in claim 3 including means for locking saidfirst latch element in its extended position.

5. The combination set forth in claim 4 wherein said locking meanscomprise a locking element mounted on said first door for rotationbetween operative and inoperative positions and engagebale with opposedsurfaces of a locking projection on said first latch element when in itsoperative position to lock said first latch element in its retracted andextended positions, respectively.

6. In combination:

(a) parallel first and second track means;

(b) first and second bypassing sliding doors respectively movable alongsaid first and second track means;

(c) first and second latch elements respectively carried by said firstand second doors and interengageable when said doors are in their closedpositions;

(d) means mounting said first latch element on said first door formovement between an extended position, wherein it is engageable withsaid second latch element when said doors are in their closed positions,and a retracted position;

(e) said second latch element being formed by a latch recess in saidsecond door into which said first latch element is insertable to locksaid doors together when said doors are in their closed positions andsaid first latch element is in its extended position;

(f) means biasing said first latch element toward its extended position;

(g) means for locking said first latch element in its retractedposition;

(h) means for locking said first latch element in its extended position;

(i) means on said first door and operable concurrently with the lockingmeans last mentioned and engageable with said first track means forinterlocking said first .door and said first track means against lateralremoval of said first door from said first track means; and

(j) whereby said doors are locked together and interlocked with saidfirst track means against lateral removal of said doors from said trackmeans when said first latch element is inserted into said latch recessand is locked in its extended position.

7. The combination set forth in claim 6 wherein said first latch elementis pivotally mounted in a slot extending through said first door, andwherein said latch recess comprises a latch slot in said second doorwhich is adapted to register with said slot through said first door andinto which said first latch element is pivotally insertable.

References Cited UNITED STATES PATENTS 2,196,001 4/ 1940 Vanderveld -952,737,045 3/1956 Holmsten 70-90 3,088,177 5/1963 Riegelman 494493,277,677 10/1966 Hurvitz 7090 FOREIGN PATENTS 159,081 2/1921 GreatBritain.

DAVID J. WILLIAMOWSKY, Primary Examiner. I. K. BELL, Assistant Examiner.

